Chain-type cutter for debarking machines



Sept. 27, 1949.. M. DOUGLAS ,3

CHAIN-TYPE CUTTER FOR DEBARKING MACHINES Filed June 2, 1947 2 Sheets$het 1 INVENTOR. MELVIN DOUGLAS Sept. 27, 1949. M. DOUGLAS CHAIN-TYPE CUTTER FOR DEBARKING MACHINES 2 Sheets-Sheet 2 Filed June 2, 1947 Face, 9

S m R 6 MU O mD N V L E M ATT'YS.

Patented Sept. 27, 1949 CHAIN-TYPE CUTTER FOR DEBARKING MACHINES Melvin Douglas, Chicago, 111., assignor to Harry A. Lowther 00., Chicago, 111., a firm Application June 2, 1947, Serial No. 751,715

2 Claims. 1 Y My invention relates to machines for stripping the bark from trees. Such machines as have come to my attention either require too long to accomplish the operation or cause the surface underlying the bark to become marred or damaged during the removal of the bark. It is therefore one object of the present invention to provide a debarking machine unit which has a shearing or drawing action, whereby to strip the, bark without causing injury to the surface underneath.

A further object is to provide a unit of the above character which works with a diagonal action, so that the bark stripping or removing force is exerted both in a forward and lateral direction to facilitate the easy removal of the bark.

Another object is to design the unit in a manner to operate astride the tree over a path of maximum width, whereby to de-bark a log by turning it only three or four times during debarking operations.

A still further object is to provide means for adjustin the unit to trees of different diameters with a view to securing the most efiicient application of the de-barking elements.

An additional object is to include means in the novel unit to render it slightly yieldable and make the operation of the de-barking elements less severe.

An important object is to design the novel unit along lines of ruggedness and simplicity.

With the above objects in view, and any others which may suggest themselves from the description to follow, a better understanding of the ina drive the shaft l8. The latter is extended to one side of the vehicle, in order that it may carry the de-barking unit clear thereof; and Fig. 1 shows that the log to be de-barked is in a posivention may be had by reference to the accom panying drawings, in which- Fig. l is a plan view of the machine, showing its application;

Fig. 2 is an enlarged plan view of the de-barking unit;

Fig. 3 is an axial section of the same;

Fig. 4 is a diagrammatic plan view, showing the de-barking operation in progress;

Fig. 5 is a cross-sectional diagrammatic View showing the de-barking unit set over a log of small diameter;

Fig. 6 is a side view of a portion of Fig. 5;

Figs. '7 and 8 are views similar to 5 and 6 in respect to a log of larger diameter; and

Fig. 9 is a diagrammatic View showing operational phases at different adjustments of the debarking unit.

In accordance with the foregoing specific reference to the drawings indicates a power vehicle at l5 which is designed to carry the de-barking unit. Thus, the vehicle frame is extended with tion alongside the vehicle, and that the de-barking unit is designed to travel over the log from end to end.

The de-barking unit is in the form of a spool, and is partly carried on a hub 25 rigidly attached to the shaft l8 by a cross pin 26. The outer portion of the unit is in the form of a pair of longitudinally-spaced circular discs 28 and 29. The disc 28 is carried by a central sleeve 30, the latter being slidably and rotatably mounted on the hub 25. The disc 29 is spaced outwardly from the hub 25. The latter receives a washer 3! at its outer end; and a compression spring 32 surrounds the shaft l8 between the Washer 31 and disc 29. The latter has a hub 35 which is keyed on the corresponding end of the shaft l8 as indicated at 36; and a small disc 31 is placed against the end of the shaft [8 as a retainer for the key 36, the disc 31 being secured to the shaft by a central screw 38.

The discs 28 and 29 are fitted with a circular series of U-bolts 4B which protrude in outward directions to receive securing nuts 41. The U-bolts are designed to secure a series of chains 42 spanning the discs 28 and 29. However, Fig. 2 indicates that the chains are diagonally directed from one disc toward the other; and the tension of the spring 32 is such that the normal condition of the chains is fairly tense.

When the machine is set with the de-barking unit over one end of a tree log, and the unit is put in rapid rotation, the progress of the vehicle toward the other end of the tree is designed to remove the bark over a portion of considerable width, such as is indicated at 45 in Fig. 4. The mean line of contact of the chains 42 which engage the log is represented by the line 46 in the same figure. Thus, the travel of the chains in the contact zone is in the general direction of the arrow 41, but the oblique position of the working chains not only acts to dislodge or strip the bark from the log, but has a. shearing action to remove the severity or abruptness of the stripping action. In other words, the action of the engaging chains is on a bias. Further, Fig. 5 shows that the chains, represented by the lines AA and B-B, combine to close or wrap themselves over the cases, the purpose is to secure the wrappingnf.

the chains over a portion of such width as will combine operative efficiency' with maximum: surface coverage, so that the log would only lhave to be turned three or four times between stripping operations to become fully de+loarked Fig;9 indicates the profile of working chains at different spacings of the discs 28 and 29.

While any suitable method may belusedfor adjusting the spacing.of the discs 28 and 29,the positive construction illustrated is preferable. Thus, the hub 25-is made with threespiral series of tapped cavitiesiill, and the sleeveSB contains a circularly spaced series of three set screws Thuathe disc 28-may'be advanced or retracted along the hub 25-with a rotary-motion to bring the set'screws 5i inline with the corresponding series of cavities iii so that the securing of the'set screws'in this-mannerfirmly tightens the sleeve "36 on'the'hub 25, -placing the disc 28 at the desired spacing from the disc 29.

It will now be evident that the novel de-barking -unit is of a compact and self-contained nature, so that itmay be mounted on any traveling carrier which providesa suitablebearing for the driven shaft IS. The assembly of the central parts of the unit is sturdy and simple; and the cluster of chains is along the periphery of the unit and therefore accessible for attention or replacement. "The unit may be set to any width according to the diameter of dogs in a given J'Obytl'ld the work negotiated and carried out with efiiciency throughout the job, whereby to strip the bark neatly and expeditiously. Further, it'is aneasy matter to adjust the discs of'the unit 'for a job where the diameter of the logs is different. Finally, thenovel unit is made of few and simple parts, whereby to be economically produced.

While I have described the invention along spe. cific lines, various minor changes or refinements may: be made therein without departing from its principle, andI reserve the right'to employ all such changes and refinements as may come withing the-scope of the appended claims.

"I claim:

1. Ailog debarking machine comprising a-car- -.rier adapted'to travel in a course parallel to the log and having a power drive, atransverse shaft driven by the :latter, and a debarking unit op- ;erate'd'by the-shaft'and engageable withthe surface of the log during the travel of the carrier, said unit comprising a pair of discs carried by the shaft in spaced relation, oppositely positioned attaching elements carried by the outer peripheral portions of the discs at equal radial distances from the shaft, a plurality of chains spanning the discs, each chain beingsecuredendwiseto a non- -OPDosite.pair'of-said attaching elements, whereby the chains are positioned diagonally between said (discs and in spaced uniform relation about said shaft, one of said discs being mounted to slide :along; the shafttoward the other disc, and yieldable means opposing movement of the slidable .disctoward theother disc to normally maintain saidrchains'in substantially taut condition.

2. A log debarking machine comprising a carrier-adaptedtotravel in a course parallel to the log=andlhaving a power drive, a transverse shaft driven by the latter, :and a debarking unit operated by the shaft and engageable with the surface of the log duringthe travel of the carrier,

said unit comprising a pair of discs disposed spacedly along 'the shaft, one disc being made fast1to the latter, oppositely positionedattaching elements carried by'thecuter peripheralportions 'of the discs at equal radial distances from-the shaft, a plurality of chains spanningthe discs, each chain being secured-endwise to anon-opposite pair of said attaching elements-whereby thechains are positioned-diagonally betweensaid discs andin spaced uniform relation about-said shaft,-a sleeve carrying theother disc and slidable on the shaft, the "latter having a plurality of tapped cavities arranged-in a plurality of spiral series, each cavity of "oneseries being circumferentially aligned with a corresponding cavity in each-of the other series, and ,a, plurality of bolts carried by the, $1eeVe, there beingone'bolt for-eachspiral-series; whereby the spacing of said discs can be varied by first removing the bolts from one setofcircumferentially aligned cavities,

thensliding and'rotating'the sleeve and securing thebolts in-a different set of aligned cavities.

MELVIN DOUGLAS.

rtnnnnnnons CITED The following references are of record.in.the

file of -this patent:

Austria 'Sept.:25, 1936 

